Apparatus for drawing topographic maps



Get. 6, 1-931. P. R. VAN BUSKIRK APPARATUS FOR DRAWING TOPOGRAPHIC MAPS 2 Sheets-Sheet 1 Filed March 8, 1950 &

- Oct. 6, 1931. R V N BUSKlRK 1,826,375

APPARATUS FOR DRAWING TO POGRAPHIC MAPS Filed March a, 1930 2 Sheets-Sheet 2 INVENTOR.

Fa j

Patented Oct. 6, 1931 PATENT OFFICE PAUL R. VAN BUSKIRK, 013 DETROIT, MICHIGAN APPARATUS FOR DRAWING TOPOGBAPHIG MAPS Applicationfiled March 8,

My invention relates to a method and apparatus for drawing topographic maps and an object of my improvements is to provide an apparatus and method for. quickly and accurately plotting transit and stadia survey data and drawing the complete topographic map. while right on theground. 1 secure this object by the method and apparatus here-' after described and illustrated in the accom-. panying drawings, in which:

Figure 1 is a plan view, partly broken away to economize space, of an apparatus embodying my invention.

Figure 2 is a detail section on the line II,

M II, Figure 1.

Figure 3 is a detail sect-ion on the line III, III, Figure 1.

Figure 4 is a detail section, partly broken away and to an enlarged scale, on the line IV, IV, Figure 2.

Figure 5 is a plan view, partly broken away to economize space, of the apparatus embodying my invention, illustrating one step in the use thereof.

Figure 6 is a view similar to Figure 5 illustrating another step in the use of said apparatus.

Referring in the first place to Figures 1 to {I inclusive, 2 represents the conventional drawing board which is square with accurate linear edges. The board 2 is cut out at its center to form a round, or cylindrical, cavity 2a, the bounding wall of which is vertical and the lower wall, or bottom, fiat and parallel to the surface of the board 2. Into the cavity 2a is fitted a metal ring 3 having a fiat peripheral upper surface 3a slightly below the'upper surface of the board 2 and parallel thereto. At a lower level and inside of the surface 3a the ring 3 is provided with a second annular surface 36 also parallel tothe surface of the board. 4: is an ivoride ring shaped to and secured upon the surface 3a, with the surface of said ring in the same plane as the surface of the board 2 and forming an extension thereof. The inner upper edge of the ring 4 is provided with the usual angular scale 4a.

5 is a metal disc fitting and adapted to turn "upon the surface 3b and having a coaxial 1930. Serial No. 434,393.

stem, or cylindrical projection, 5a extending down from its center and fitting in a cylindrical aperture in the board 2. 5b are spiral surface of the plate, or disc, 5; its upper surface forming a continuation of the upper surface of the board 2 and the ring l. 6b is a radial dove-tailed slot in the disc 6, one of its edges being accurately radial and intersecting the circumference of the disc 6 so as to form the index point to coact with the scale 4a. from said index point along the periphery of the disc 6. 7 is a strip having an ivoride upper surface and a linear scale along one of its edges adapted to engage and slide radially into the slot 6?), the surface of said strip forming a continuation of the surface of the disc 6.

(Figure 4:) is a rod fitting into an aperture extending inward from the edge of the board 2 and having spiral teeth 10? on its inner end adapted to engage the teeth 56 on the projection 5a. 10a is a milled disc on the'outer end of the rod 10, by which said rod may be turned to adjust the plate 5 with the disc 6 thereon to difi'erent angular positions;

, 8 is a metal plate set in and secured to the lower surface of the board 2 coaxial with the cavity 2a. 8a is a ring adapted to be secured upon the lower surface of the plate 8, concentric therewith and having its inner portion spaced from and parallel to said plate. 9 is a ferrule screwthreaded on its inner surface to engage the upper end of a tripod and having an annular flange at its inner end which engages under the flange of the ring 8a so as to make a tight joint upon which the board 2 may turn. 89 is a set-screw passing through the ring 8a and engaging the flange 9a of the ferrule 9, by which the board 2 may be clamped into any angular position at which it is set. 11 represents a sheet of transparent vellum tracing cloth, celluloid, or other transparent mate- 6a is a Vernier scale extending from j to is directly over the backward-exrial passing over the whole face of the board 2. i

The method embodying my invention is described as follows:

If one wishes to map a certain lot, or piece of land, he would set up the above described board upon its tripod in the field and dot a point 5' uponthe sheet 11,rrepresenting'fori instance the southwest corner of the lot, and, place this dot directly overthe center of the disc 6. The board 2 is' turned until thezeroof the scale la and the meridian line xw is approximately north. The center section, or disc 6, is then rotated until its indezgpoint points to zero. The distance to the northwest-corner is: then read by stadia. and that distance is: laid off) along .thescale 7a, or; an, extension thereof,. and aiidot placed :upon, the paper .to indicate this location and. this.

gClOt' may .beiconnected with. that overathei.

center of the disc (Sbya line to represent-the westline of the lot, or a line may-be drawn I above the. meridian line w.00 to CODStltUbB v a direct north and south orienting line;

Different points upon the surface of the lot are now located as follows. The angular-v direction from the southwest corner to each pointy is; measured by. the transit and its distance taken by stadia and the CllSC-6'1Sm then turned; tolthat angle and the distance marked otllupon the scale 7a. This is done for all desirable points within easy sight of the postion j. 1n this way various points; a, lac, d, e, f, g, It, 2' upon the boundary of" r a pond 12,.for instance may be located and the outline of the pondbe dotted in by con nectingthese points.

A point may then be located-.by ataking its angular position :by thetransitland turning the disc 6 to theangle observed and. then accurately measuring by a chain: the distance between point to point/c and setting that off on the scale 7a,or an extensionthereof. The transit isthen moved tothe point in;the.-,-

izglotcorresponding to thenpoint is, oriented with reference to the point. j, and theangle i taken between the line 70 and the line km to: 1 the southeastcorner mand the distancerlcm accurately.measured by a chain and the dis ta-nee jm may then be accurately calculated.

A point .a between the southwest andv northe west corners of thelot may then beiselectedand the anglefrom j to a may be measured and the distance from is to. a measured and ..the distance jnaccurately calculated; Thisdata is kept as traverse notes.

The sheet 11 is now moved until the point- 70 comes directly above thecenter of the'disc 6 and is oriented either by placing the line tension of the radial scale'Ta or by bringing the point g on to tliemeridian linens-m,- point 3 beingscaled-the same distance east-of the meridian av, won Figure 5 as pointic V scales.

'tionn- Different points 9a may then be located by stadia and angular measurements, as above described, and dotted down directly upon the map without the necessity of making notes and transferring the notes.

The elevation of each point as it is located is also observed and maybe noted as the pointi is locatedaipon the map and' then-contour lines drawn between points of equal altitudes, as indicated in Figures 5 and 6.

Inthis' Waytheentire' map can be made directl in the field without the necessity of taking notes and transcribingthe same, or translating them into graphic notes.

What I claim is:

1.: The: combination of :a drawing board, a rotatable disc set in said drawingboard with itssurface flushwith the surface of the drawingsboard, zsaid disc and drawingboard beingiprovided .with 'an index :and scale respectively, adapted to indicate the angula rposition of said disc relative :to said-board anda radial scale upon said "disc as and for: the. purpose. described.

2. Apparatus for use in plotting 'survey ingrdata consistingrof 21- CllZLWl11g bOHELl, a

rotaltabl'erdisc setin saiddrawingboardwith its surface flush with thesurfa ce of thedraw ingboarchsaid disc and drawing board being provided with an index and scale 1'espec-- tively adapted to indicate theangular position of said disc relative to sa-i'd board,-aradial" scale upon said disc as and for the purpose describedand a sheet of translucent material adapted to lie flat upon the surface .100 of said disc and board 3.;The combination-of a drawing board, a f rotatable disc set in said drawing board with 1 its surface flush with the surfaceof the drawing board, said disc and drawing board being: provided-with an index and scale resepectively adapted to indicate the angular position-of said disc relative to said board an d a radial scale upon said 'disc as and for the purpose.described;- said-scale being re-" movable and replaceable.

45The combination of a drawing board, a rotatable disc-fixed in said drawing board with its surface in continuation oftl'ie'sui face of said board, said disc an'd boar-d "be" mg provided with an index and seale respeo' tiv'ely adapted to measure the 'ang'ular posi tion of 531d disc relativcto said board, said disc beln g pI'OVlLlGdJ WlthEL slot extending radially from its per-ipher-y to itscenter and a strip of 1 material :havinga scale thereon adapted to removably fitinto said slotjwith itssurface flush withthe surface of said disc;

In testimony whereof, I sign: this specifica- -1 PAUL R; VAN i BUSKI RK; 

